1. Field of the Invention
This described embodiments relate in general to nano technology and, more specifically, to a method and apparatus for producing a nanocomposite material reinforced by unidirectionally oriented pre-dispersed alumina nanofibers.
2. Description of the Related Art
Nanotechnology deals with developing materials, devices, or other structures having at least one dimension sized between 1 and 100 nanometers. Nanoparticles are the particles having at least one dimension sized between 1 and 100 nanometers. On the other hand, nanofibers are defined as fibers with diameters less than 1000 nanometers. Nanofibers are widely used for manufacturing nanocomposite materials having enhanced properties, such as polymers reinforced by nanoparticles.
At the present time, several kinds of nanoparticles which can be used in the production of nanocomposites are known in the art, including, without limitation, carbon nano tubes (CNT), nano powders produced from silicon carbide, alumina and other materials. Also known in the art are various methods for nanoparticle or nanofiber fabrication, including, without limitation: hydrothermal process, sol gel process, mercury mediated process, flame-spray method, vapor-liquid-solid process as well as electrospinning method.
It should be noted that due to their large surface area, nanofibers such as carbon nanotubes tend to agglomerate during the production process of nanocomposite materials. On the other hand, in the agglomerated state, many of the beneficial properties of the nanofibers and, in particular, their reinforcing ability, are compromised. This leads to only marginal improvements in the properties of nanofiber-reinforced composites compared to the conventional materials.
To remediate the aforesaid agglomeration tendency of nanofibers and the associated degradation of material properties, various nanoparticle dispersion methods have been devised. Exemplary dispersion techniques include ultrasound-assisted dispersion described in U.S. Patent Application Publication No. US 20090275689 A1, incorporated by reference herein. Additional dispersion methods involve exposing the agglomerates forming during nanocomposite production to hydrodynamic stresses as described, for example in European Patent Publication No. EP1818358 A1, incorporated by reference herein.
An additional challenge facing the nanocomposite materials production is the difficulty in achieving a unidirectional alignment of reinforcing nanoparticles within the nanocomposite.
Thus, new and improved techniques for manufacturing of nanocomposite materials reinforced with unidirectionally aligned nanoparticles are needed.